| 摘要 |
A foundation pile construction method, wherein the method includes: setting steps (S13, S14) for setting a plurality of expansion ratios (ω) representing the proportion of the inside diameter of an expansion excavation unit (5) relative to the outside diameter design value at a predetermined position of the tip part (10a) of a foundation pile (10); a design-support-strength-measuring step (S16) for performing a load test with regards to one or more expansion ratios selected from the expansion ratios at a construction site to which the foundation pile is physically provided, and measuring the design support strength for the foundation pile for the respective expansion ratio; a design-support-strength-determining step (S17) for determining whether or not the product of the design support strength and the number of foundation piles to be used is equal to or greater than the desired design load acting on a pile foundation formed by the foundation piles; an optimum-expansion-ratio-determining step (S18) that, when the design support force of the foundation pile for a plurality of expansion ratios is measured in the design support force measurement step, determines the smallest of the expansion ratios satisfying the criterion that the product is equal to or greater than the design load to be the optimum expansion ratio for the expansion excavation unit; and an expansion-excavation-unit-forming step (S19) for forming the expansion excavation unit on the basis of the optimum expansion ratio. |
